Energizing vacuum discharge device by alternating current



Dec. 25, 1928. 1,696,233

R. A. HEIESING ENERGIZING VACUUM DISCHARGE DEVICE BY ALTERNATING CURRENTFiled Nov, 6. 1922 //7Ve/1f0/ Raymond A Hal's/k7 y z-l k framed Dec. a5,192s.

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[AUNITED-STATES PATENT OFFICE.

'mw'xonn A. imismo, or MILLIBUBN, NEW mnsn'r, nssmnon 'ro wns'mrm unc-TRIO COII'AN Y, INCORPORATED, 015 NEW YORK, N. Y., A CORPORATION 01' NEWmmnexz'me vacuum mscnnnen nnvrcn BY ALTERNATING cmmmrr.

I Application filed November 6, 1822. Serial No. 599,200.

I I ]This; invention lirelates to methods of operating electricdischarge devices from an a alternating current "supply source and tosystems operating in accordance with said methods.

An object of the invention is to reduce the number of tubes needed inthe modulating systemsupplied with alternating energizing current forproducing and modulating high frequency waves.

Another object is to increase the efiiciency of systems whereinmodulated high frequency waves are produced at relatively low power andthen amplified and radiated at high power.

Another object is to so organize such a i system that tubes ofa singlekind only, or

of a very small number of kinds of tubes, maybe utilized wherebyinterchange of tubes is facilitated and the necessity for de' signingnumerous types of tubes is avoided.

A further object is to reduce to a minimum the necessary number ofphases of alternating current supplied to a system of as possible thedisturbances introduced into the system by the utilization ofalternating current supply instead of direct current.

The invention is particularly illustrated in connection with a radiosystem which consists in general of a modulator and an amplifier foramplifying the energy of the high frequency waves produced by themodulating system. The amplifying system is supplied with alternatingcurrent and serves not only to rectify its own operating current, butalso servesto rectify the current supply for the modulating system.

Various advantageous and novel features of an arrangement of this sortwill occur to those skilled in the art from a perusal of the followingdetailed description taken in connection with the accompanying drawingwhich is a circuit diagram of an arrangement embodying the invention.

i In thissystem four power-amplifying and rectifying tubes 1 aresupplied with space current from two phases 2 and 3 of alternatingcurrent supply which are preferably 90 out of phase. A quarter-phasegenerator is illustrated as theprimary source of ower.

Although four tubes andtwo phases are chosen for purposes ofillustration, it will be obvious that two of the tubes and one phasemight be omitted or that three, six, or systems having any other numberof phases might be used. Each of the different phase supply circults isdivided into two parts by means of a transformer 4 having its secondartapped at the middle point which in e 'ect gives four phases of current90 apart, each supplying one tube.

The rectified current path for a single one of these four phases willnow be traced. Beginning at the central tap of the secon ary of thetransformer 4 positive current passes in a direction as indicated by thearrows from the anode to the cathode of a tube 1 through the secondarywinding of transformer 36, conductor 5, and choke coil 6 to a point 7.-At point 7 the current divides, part passing through the conductor 8 andthe variable impedance tube 9 to the cathode of the tube, thencereturning to the.

point of beginning along conductor 10. From the point 7 the otherportion of the current passes through choke coil 11 and the tube 12 tothe cathode thereof, thence returning likewise through the conductor 10to the point of beginning.

The coil 6 is designed to prevent the passage of current variations ofspeech frequency and hence has a large inductance.

The coil 11 is designed to pass current variations of speech frequencyand prevent the passage of high or radio frequency current variations,

The tube 12 has associated with itself.

. alternative path from the anode .to the cathode of tube 12 extendsfrom the anode through condenser 19 to a point on the con ductor 5.Condensers 19 and 15 are of such capacity as to be of highimpedance tospeech frequency currents. From a point between the condensers 14 and15, there is a connection to the grid of the tube 12 through a stoppingcondenser 20. p

The arrangement of elements just described when r0 erly adjusted acts asa enerator of ig 1 frequency oscillations. This is an oscillator of thetype illustrated in Figs. 3 (f) on page 69 of the proceedings of the I.R. E. vol. 6, No. 2 April 1918. Any convenient oscillating circuit mightbe used instead, The oscillations are modulated in amplitude inaccordance with signals in a manner now to be described.

Choke coil 6 tends to maintain constant the flow of the total directcurrent supplied to the tubes 9 and 12. Consequently when the impedanceof the tube 9 is increased or decreased the current flowing through thetube 12 is accordingly increased or decreased and the amplitude of theoscillations varies simultaneously.

A speech or other signaling frequency circuit is represented by amicrophone circuit 21 coupled by means of a transformer 22 to the inputorgrid-filament circuit of the tube 9. As sound waves impressed upon themicrophone through the circuit 21 vary the impedance of the tube 9, theam litude of the oscillations produced by the tu e 12 will varyaccordingly.

A leak path for direct current extends from the grid of the tube 12through a high resistance 24 to the middle point of a resistance 25which is connected across the cathodes of the tubes 9 and 12. When thetube 12 is oscillating, direct current will flow in the grid circuitthrough resistance 24. By means of the variable tap on the resistance 24the grid of the tube 9 is caused to have a suitable average negativepotential with respect to its associated cathode for the purpose ofpreventing distortion by the tube 9 and increasing its efficiency. Achoke coil 23 designed to have high impedance to speech frequencycurrents prevents such currents, induced in the microphone circuit 21,from producing speech frequency voltage variations on the grid of tube12. A condenser 23 is of low impedance to speech frequencies and permitscurrents of such frequencies to flow in the grid-filament circuit oftube 9.

The high frequency waves produced by the oscillation generator areimpressed across a combination of impedance elements 26, 27 and 28 whichare included in the gridfilament circuit of the amplifier tubes 1. Astopping condenser 29 separates the grids of the tubes 1 from any otherdirect current source in the oscillation generating system.

The elements 26, 27 and 28 may be adjusted to regulate the inputimpedance and the grid potential of the amplifiers 1. The grid potentialis determined by the value of the resistance 28 and the impedance tohigh frequency is determined chiefly by the adjustments of inductance 26and capacity 27. The grid potential determines the efiiciency of thetubes 1, and the high frequency impedance is adjusted to ive efiectiveener transfer from the osci lator circuit to tie amplifier circuit.

Direct current flows through inductance element 26 and the highresistance 28 which consequently constitute a leak path for directcurrent between the grids and the oathodes of the tubes 1.

The path for the high frequency waves in the anode-cathode circuit ofthe tubes 1 is from the anodes through the capacities 30, and anadjustable high frequency transformer primar 31 and condensers 32 and 33to the catho es. The energy of the high frequency waves is thusimpressed upon any suitable load circuit, as for example, the radiatingantenna circuit 34, which includes the coil 35 clectromagneticallycoupled to the coil 31.

The cathodes of all the tubes may be heated from any suitable currentsource, but preferably from one of the phases 2, 3. As illustrated, aconnection is made across the conductors of the phase 2 to thetransformers 36 and 37. The secondary of transformer 37 is connectedacross the cathodes of the tubes 9 and 12 and the secondary oftransformer 36 is connected across the cathodes of the tubes 1.

In order to reduce the effect of the alternating current variations inthe anode circuits of the tubes, the anodes and grids are connected tothe midpoints of impedance elements connected across the cathodes. Inthe case of low frequency tube 9, this impedance element is preferably aresistance 25, but for the other tubes capacities 17, 18 and 32, 33 areprovided. Choke coils 41 prevent the passage of high frequency currentsthrough the windings of transformers 4.

In the operation of the system, each tube 1 will be rectifying currentfor about onehalf the time. The several impulses of rectified currentwill overlap so as to produce a practically continuous space currentsup- 3 ply for the tubes 9 and 12. This current will be smoothed out bythe action of the condensers 30 which are selected in capacity not onlywith a view to passing high frequency waves, but also to exercise amaxi- 3 mum smoothing effect upon the rectified current.

Since the four tubes 1 are each operating approximately one-half thetime, the total current supplied to the tubes 9 and 12 will be aboutthat which would be required for two tubes 9 and 12 similar in design tothe tubes 1 because the tubes 9 and 12 are continuously operating.Howcver, if it is desired to use more tubes 1 or tubes of greater powercapacity the variable resistance 38 may be shunted across the spacecurrent supply leads to the tubes 9 and 12 and adjusted to shunt offsuch portion of the current, rectified by the tubes 1, as may bedesirable.

If the current supplied by the tubes 1 is exactly that requisite forthetubes 9 and 12 the resistance 38may be omitted or adjusted to a veryhigh value. The resistance 38 may beany resistance device, or a directcurrent operated "device, which will not interfere with the 0 ration ofthe rest of the system and there ore the ener y dissipated in the f rentsupply source, by opening the primary circuits of transformers 4 andoperating the 39to connect the battery 40 into circuit.

- The system above described is typical of variouspossible'iarrangements operating in accordance with the same generalprlnclples which may be devised and therefore the invention is notlimited to the exact arrangements illustrated, but only in accordancewith the sco 'of the appended claims. The

system is o viously a plicable to energy transmission. over. con uctivecircuits for which purpose a line is substituted for the antenna 34.

Having described one'form of the invention, the novel features believedto be in- 'herent therein are now set forth in the appended claims.-

-- What is claimed is:

1. In combirtion, a modulating system, a svstem for amplifying the'wavesproduced .thereby, an alternating current supply, and

free the energizing current for the modulating system. I e 2. Incomb'nat1on,a constant current modmeans whereby the amplifying systemrectiulating system. in combination with an amplifier for amplifying themodulated waves produced thereby and also for rectifying the current, tobe supplied to said I modulating system.

. waves, and a source of space current, said rcpeater being in serieswith sa1d source 0 3. In combination, a repeating device, a

- device for producing modulated waves, a device of varlable impedancefor cooperating with said device in producing modulater space current,and said modulating device and variable impedance device constitutlng.aparallel combination in series with the i ."scries combination thusformed.

4. In combination, a source of a number ofyphases of alternatingcurrent, a rectifying device supplied by each phase 1n comd 'binationwith a constant current modulating system COIIIPI'lSIIIg dGVICGS similarto sa1d rectifying devices and having one-half the total power -capacitythereof.

,5. In combination, a space discharge device 'havingJa-plate or anode, agrid and a cathode, a source supplying alternating current to saiddevice, in combinat on with a repeatingsystem of discharge devices forrepeatrn system rectifies the current supplied to sa'i space dischargedevice.

6. In a system for modulating and amplifymg carrier waves, a device forproducing modulated waves, a variable impedance device and an amplifyingdevice, each of said devices having an anode-cathode circuit, arid-cathode circuit and a filament circuit, 1n combination with a sin lesource of alternating current for supplyin filament heating current,space current rom the anode to the cathode, and current to maintain thegrid of each device negative with respect to its associated cathode.

7. In combination, a wave amplifier a device for supplying waves to beamplified to the input clrcuit of said amplifier, said device duringoperation requiring a supply of energizing current, an alternatingcurrent source, and means whereby said amplifier rectifies and suppliescurrent from said source to said device.

8. In combination, a high frequenc' discharge device and a low frequencdisc arge device each having a heated. lamentary cathode in combinationwith a transformer for supplying heating current to said cathodes inparallel, said high frequency device having its cathode shunted by adivided capacity to the middle point of which its anode connection ismade, and said low frequency device having its cathode shunted by adivided resistance to the middle pointof which its grid circuitconnection is made. 9. In a high frequency amplifier, a series ofrepeating tubes individual to phases of alternating current forsupplying each tube, said tubes having a common output impedanceelement, and individual condensers connecting them to said impedanceelement.

10. In combination, a high frequency amplifying system arranged inseries with respect to a modulating system which is supplied withenergizing current through a circuit connecting said modulating systemto said amplifying system, and a shunt element f across the'circuitconnecting said systems for regulating the current supplied to saidmodulating system.

11. A transmission circuit comprising a constant current system,including space discharge devices, for producing a signal modulatedcarrier wave, a plural-phase alternating current source, and a spacedischarge system for amplifying the modulated carrier wave and forrectifying the phases of said alternating current to supply energizingcurrent to the discharge devices of said modulating system.

12. A system for generating high power high frequency electricalcurrents comprising a source of low frequency alternating currents,means for impressing sa1d low frequency currents upon a vacuum tube withwhich are associated self-oscillation producin circuits, means forimpressing said low requency currents upon a pair of vacuum tubes withwhich rectifying and amplifying circuits are associated, meansassociated with the said air of vacuum tubes for impressing the saidrectified currents upon the circuits of the first mentioned vacuum tubeand means for impressing the oscillations in the circuits of said tubeon the circuits of the said pair of vacuum I tubes.

13. A system for generating high power high frequency electricalcurrents comprising a source of low frequency alternating currents,means for impressing said currents upon the plate-filament and filamentcircuits of a vacuum tube with which are associated self-oscillationproducing circuits, means for impressing said low frequency currentsupon a pair of vacuum tubes, means associated with said pair of vacuumtubes for the simultaneous rectification of said low fre uency currentsand amplification of osci ations produced in the first mentioned vacuumtube.

14. A system for generating and radiating high power radio signalscomprising a source of low frequency alternating currents, means forimpressing said currents upon a vacuum tube with which are associatedselfoscillation producing circuits, means for impressing said lowfrequency currents upon a pair of vacuum tubes with which rectifying andamplifying circuits are associated, means ass ciated with said pair ofvacuum tubes for impressing the said rectified currents cuits of saidtubes upon a radiating system.

15. In combination two space discharge tubes in tandem whereby outputwaves supplied by the first tube are impressed upon the second tube andrepeated thereby withbut change of frequency, a source of alternatingcurrent, and connections of the space paths of said tubes to saidsource, whereby the second tube serves to rectify alternatin currentfrom said source to sup ly ung-directional space current to thefi rst tue. 1

16. In combination two space discharge tubes in tandem whereby outputwaves supplied by the first tube are im ressed u on the second tube andrepeated t ereby without change of frequency, a source of alternatingcurrent, and connections of the space paths of said tubes to saidsource, whereby the second tube serves to rectify alternating currentfrom said source to supply unidirectional space current to both saidtubes.

In witness whereof, I hereunto subscribe my name this 3rd day ofNovember A. D.,

RAYMOND A. HEISING.

